def addition_and_subtraction(stringy: str) -> int:
    """
    Return the value of equation.

    The equation only consists of plus (+), minus (-) and digits (0-9).
    There are no 2 consecutive operands. In the end, there is no operand.
    In the beginning, both "+" and "-" are acceptable.

    "1+2"  # -> 3
    "-1+21"  # -> 20
    "+1-1"  # -> 0

    :param stringy: Equation.
    :return: The result of equation.
    """



def equalizer(unequal: list) -> list:
    """
    Equalize numbers between bigger or smaller numbers.

    [1, 4, 1]  # -> [1, 3, 1]
    [1, 2]  # -> [1, 2]
    [1, 4, 1, 0, 2]  # -> [1, 3, 1, 1, 2]

    :param unequal: Unequalized list.
    :return: Equalized list.
    """